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Date: Mon, 3 Mar 2008 00:43:10 +0100
Reply-To: Marcus Boerger <helly@php.net>
Message-ID: <1254814899.20080303004310@marcus-boerger.de>
To: Rasmus Lerdorf <rasmus@lerdorf.com>
CC: Stanislav Malyshev <stas@zend.com>, internals@lists.php.net
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Subject: Re: [PHP-DEV] [RFC] Replace the flex-based scanner with an re2c [1] based lexer
From: helly@php.net (Marcus Boerger)

Hello Rasmus,

Monday, March 3, 2008, 12:25:52 AM, you wrote:

> Stanislav Malyshev wrote:
>> Hi!
>>
>>> be much easier, switching to re2c promises a much faster lexer. 
>>> Actually,
>>> without any specific re2c optimizations we already get around a 20% 
>>> scanner
>>
>> I think 20% faster is very cool.
>> However, as I understand re2c is not a standard tool found everywhere. 
>> So what happens if you wanted to use it on some exotic system where 
>> re2c is not readily available as manintainer-supported software? Also, 
>> flex is available on Windows for example as part of cygwin, while I 
>> don't see re2c there.
> I don't think this part is a concern since we have required re2c for 
> quite a while now to build many critical parts of PHP.  People who 
> actually need to regenerate the parser files are the same people for 
> whom it is trivial to figure out how to install re2c.  And yes, it would 
> of course be good to use a released version of re2c, but I think by the 
> time 5.3 is ready to go the version of re2c we need will be out there.  
> Since it is Marcus' baby, he can just push it out, I don't think this is 
> a stumbling block either.  Some of the new stuff in re2c was 
> specifically added to make it easier to write a PHP parser, so I don't 
> think backporting to an older version is really an option.

Right. The current re2c development cycle is solely dedicated to be able
to rewrite the PHP scanners. I will update re2c whenever necessary during
the remaining development cycle and release a new stable release before we
release PHP 5.3.

Best regards,
 Marcus